You don't want to break the engine in on the stand as Ol' Ron said. But to my thinking working out a few bugs on the stand with short runs a few times won't do to much.
Is it necessary. nope. But as mentioned test stands or easy to make. But not easier then pulling the motor again. maybe.
Yblock I was messing with on stand to see if it would run.
https://www.youtube.com/watch?v=PbMD...ature=youtu.be